Selective Radiosensitizing Effect of Amorphous Hafnia Modified with Organic Quantum Dots on Normal and Malignant Cells

—Aqueous sols of hafnia modified with organic quantum dots, which exhibit pronounced luminescent properties, have been synthesized by hydrothermal treatment of amorphous hydrated hafnium dioxide in the presence of ammonium citrate. It has been shown that malignant human cells of the U-251, MCF-7, and MNNG/Hos lines take up the resulting nanoparticles to a significantly higher degree than human mesenchymal stem cells. Under X-ray radiation (15 Gy), the resulting nanoparticles exhibit radiosensitizing properties against malignant cells of the U-251 and MCF-7 lines, significantly reducing their viability. On the contrary, in relation to human osteosarcoma cells of the MNNG/Hos line, the radiosensitizing properties of the obtained material are much less pronounced.